1. Field of the Invention
The present invention relates generally to electronic copier apparatus such as electrostatographic copiers and methods for using same, and more particularly, to electronic copier apparatus and methods for making collated sets of reproductions.
2. Brief Description of the Prior Art
As noted in U.S. Pat. No. 4,076,408, it is well known in the prior art to provide convenience copiers with document feeders that present the individual document sheets to the copier, one-after another or seriatim, in a manner suitable for producing collated copies without a sorter.
In such apparatus, the original comprising a set of individual sheets, is automatically circulated for presentation to an optical exposure station, one sheet after another for copying.
More recently, an improvement in copying is provided by using electronic collating copiers such as described in U.S. Pat. No. 4,949,190. In such electronic copiers, image data is "read" by scanning an original document sheet with an electronic scanner so that optical image information on the original is converted to a stream of electronic video or image data. The video data may be stored in multi-page buffer memories. When a plurality of copy sets of a multi-page document are to be produced as a copy job, the stored video data for each page are repeatedly sent to the printer in proper page order such that the reproduction sets are automatically collated without use of a sorter.
As used herein, the term "electronic copier" is meant to refer to apparatus arranged for reading the image information on an original document sheet and converting the information to electronic data and for reproducing such image information on a receiver or copy sheet, which is a "hard copy." The term "copy job" is used in its conventional sense and implies operation of the apparatus in a copier mode to produce one or more hard copy sets from a production job requiring copying of an original document having one or more hard copy pages in accordance with predetermined parameters requested for producing said copy sets.
In known copiers such as the KODAK 1575 Copier/Duplicator manufactured by Eastman Kodak Company, Rochester, N.Y., a copy job to be copied may have its originals scanned in via use of the platen or an automatic document feeder (ADF), but not both except when using key sheets in the ADF and a pause mode is selected for the key sheet. In this electronic copier, the user is allowed to select the platen or the ADF at the beginning of a job as the source for inputting originals. If the ADF is selected, the user is allowed to place key sheets in the original stack at appropriate locations to cause the ADF to pause when the key sheet is advanced by the feeder and sensed by key sheet sensors in the feeder. At this point, the operator of the electronic copier may request that a document sheet placed on the platen be scanned. On this electronic copier, a key sheet is a paper sheet with slotted holes which signals the copier that a different combination of features should be used and/or where pause has been preselected for key sheets causes the pause mode to be entered by the electronic copier and a prompt displayed allowing the operator to have scanning of one of the original document sheets by placement on the copier's platen. The key sheets are placed in the set of original document sheets directly before the original document sheet in the stack of originals that is to be changed or in which copies of the original document sheet scanned off the platen is to be positioned in finished copy sets. For every page to be scanned from the platen, a separate key sheet must be used. Key sheets may also be used for inserts or covers. When the ADF input paper tray becomes empty, the scanning of originals is complete, therefore the job is complete. If the platen is selected at the start of a job, the ADF cannot be used as a source of document input. However, one or more originals may be scanned from the platen in what is known as a collate off platen mode and a copy job produced using this mode.
The above noted KODAK 1575 Copier/Duplicator has the capability of merging the information from two separate scanned-in document sheets into one output copy. This feature is called image overlay, and can be applied for the entire job or for a designated pair of sheets within a job. Memory capacity in a buffer memory associated with the scanner forces a size limitation of the original to 8.5".times.11" portrait or A4 portrait size paper. For feeder jobs with job level image overlay selected, every two consecutive scanned document sheets will be combined. Only scans from the feeder can be combined unless a pause key sheet stops the scanning and allows for a scan from the platen. At this point, the operator must intervene and press the START button for each scan of an original from the platen glass. After the platen scan(s), the operator must press the START button again to resume copying from the feeder.
The inventors have recognized that an electronic copier that is more flexible in allowing inputs from the ADF and the platen for scanning of a copy job requiring an image overlay mode would be highly desirable.
It is therefore an object of the invention to provide an electronic copier with improved flexibility in entry of image data for a copy job involving image overlay.